Is this Itinerary doable??

I can try and take a crack at this - but I often hesitate to even comment on such expansive type trips because in lots of cases, I haven't been to some or most of the places. You your scenerio - I have not ever been to Amster, London, Belgium...so I don't want to comment to much on those as it wouldn't be educated. However, overall you have a good start. I think what you have is doable if you spread those 20 days over the 30 that you have. I wouldn't add any more stops.

In my opinion - any major city deserves at least 4 days (Paris/Rome/London), areas to explore deserve 3 days (like Rhein Valley or Bernese Oberland), tiny places deserve at least 2 days (like Rothenberg or Hallstatt). That has worked well for me.

So having said that, Munich I would give 3 nights minimum. Switzerland is pretty vague. I think most people would recommmend the Bernese Oberland and for that I would give yourself 3 nights. Keeping in mind it will take the better part of a day just to train there from Munich. The Rhein Valley is great for 3 if not 4 nights with lots of exploring to do all around - Koln, Mosel Valley, castles.

Also, I think a lot of people agree that the Black Forest is not an area that a lot of people rave about - but you may have good reasons you want to go. Just mentioning it. If you do opt not to go - look into Rothenburg to hit on your return back home. Great little place.

You have the great advantage of not having to deal with jetlag or losing travel time getting to and from EU.

Best of luck - but it looks like you got a very good start. Look at all your train travel and how much time it is going to take to get around. I think most people (not from the EU) make the mistake of under-estimating that time.

Hey, Helpline Helpers: I think maybe this OP got lost and is rapidly settling to the bottom of the page, unanswered.

Unfortunately, the day by day itinerary is not formatted to make reading easy.

Look at your itinerary. Every other day says "to" or "toward". A lot of those "to" days involve considerable travel time (Munich to Switzerland to Belgium, Amsterdam to London, London to Hamburg). Unless your objective is to explore the trains of Europe, slow down. Spend more time in places.